Process of destructive distillation



C. TURNER.

PROCESS OF DESTRUCTIVE DISTILLATION.

APPLICATION FILED JUNE 12, I9|8.

1,886,264, Patented Apr. 6, 1.920.

RGHARLES TURN-ER, or IRLAM, ENGLAND.

PROCESS OF DESTRUCTIVE DISTILLATION'.

Specification of Letters Patent.

' Patented Apr. 6, 1920.

Application filed June 12, 1918. SeriaI'No. 239,637.

7 '0 all whom it may concern:

Be it known that I, GHARLns TURNER, a subject of the King of Great Britain, resldmg in Irlam, England, have invented certalnnew and useful Improvements 1n Processes of Destructive Distillation, of whlch the following is a specification.

Q I have discovered that destructive distillation of carbonaceous materials, such as wood, peat, lignite, oilshale, or coal, may be advantageously conducted in a vessel WhlGh 1s alternately closed until the pressure therein has attained a desired maximum and then opened, whereby the pressure is reduced rap: idly from this maximum. By the term destructive distillation I do not include the cracking of hydrocarbon oils by heating the liquid 011 in mass.

The products obtained by conducting the destructive distillation in this manner may be different in respect of proportion or nature or both from those obtained when the pressure is not purposely varied, the outstanding difference in the case of most kinds of carbonaceous materials being the larger proportion of oils and smaller proportlon of pitch.

The invention is applicable with any mode of heating, whether external or internal, but inasmuch as the known method of heating which consists in passlng heated elastic fluid over or through the material in the vessel, affords particular facility for varying the pressure within the vessel, this mode of heating is generally preferable.

The invention may be applied for instance by charging the material into a retort or like container having one or more inlets for a heating agent, such as superheated steam, and one or more outlets for the agent and the volatile products of carbonization which accompany it. The outlet is alternately closed or throttled and opened for passage of the elasticfluids by, for instance, a suitable valve which may be automatically operated by known mechanismdepending for itsaction on the pressure within the container or on some external force. The superheated steam or other heated elastic fluid is passed into the container for a certain period of time or until the pressure as indicated by a manometer has risen to the required value. The valve then opens or is opened for a certain period .of time or long enough to allow the pressure within the container to fall to that which has been decided upon as the lower limit.

T OFFICE.

The outlet from the container is connected with any suitable system of plant for collectmg products of carbonization constructed in respect of dimensions with due regard to the sudden flow of products and agents at each reduction of pressure.

Since the alternation of pressure is the cause of the beneficial effect of the invention, it is in most cases siderably the absolute initial and final pressures chosen, and when it is known to be advantageous to carbonize under pressures below that of the atmosphere the invention is still applicable provided such pressures are alternately lowered and raised.

The invention is applicable to processes of continuous and semi-continuous carbonization as well as to processes of intermittent carbonization. Obviously in continuous processes greater attention than usual must be paid to the gas-tight character of the charging and discharging devices.

The invention being applicable to a variety of carbonaceous materials, requiring, as is known, different conditions of temperature and rate of carbonization, both of which affect the range of pressure and the periods of alternation according to this invention, it is impossible here to prescribe the best conditions for operating; these can be determined only by experiment with due regard to the nature and proportion of products required.

Asa specific example, however, I will recite the procedure I have adopted in carbonizing peat with the object of obtaining the maximum yield of oils, the accompanying drawing being a diagrammatic axial section through the retort used.

A cylindrical iron retort a 2% feet in diameter and 7 feet high is connected at 6 through a stop valve with a boiler (not shown) adapted to generate steam at 20 lbs. pressure above atmospheric, and at 0 through a stop valve d with a condensing plant (not shown). This retort is provided possible to vary conduring the heating operation. When the retort has been charged steam is blown in at 6- while valve d is open, until the air in the retort has been expelled. Valve d is now closed and steam from the boiler is passed through a superheater capable of raising its temperature to 500 C. and into the container until the manometer indicates 5 lbs. per square inch pressure; the valve 1) is now closed and valve 0! opened, by hand, until the pressure as indicated by the manometer has fallen to 2 lbs. e'r' square inch, whereupon the valve d 1s closed and the inlet' valve opened and the pressure allowed to rise again to 5 lbs. per square inch, and so on, the operations being repeated until observation of the condensing plant shows that there is no longer any substantial distillation of products.

Having thus described the nature of the said invention and the best means I know of carrying the same into practical eflect, I claim 1. A process of destructive distillation of solid carbonaceous material, which process consists in heating a charge of the material in a closed vessel until the elastic fluid pres.- sure therein has attained a selected maximum and thereupon relieving the ressure in the.

vessel by causing the elastic uid to expand into a condenser, and repeating these operations upon the same charge until distillation 1s complete.

2. A process of destructive distillation of solid carbonaceous material, which process 3. A-process of destructive distillation of solid carbona eous material, which process consists in passing into a closed vessel containing a charge of the material superheated steam so that the elastic fluid pressure within the vessel rises to a selected maximum and thereupon openin .the vessel to a condenser and repeating t ese operations until distillation is com lete.

In testimony whereo I have signed my name to this specification in the presence of two subscriblng witnesses.

CHARLES TURNER.

Witnesses:

JAMEs LnrroH, J OHN' Emma SMITH. 

